The person who comes to mind is Minh, a classmate from my engineering course in Da Nang. We shared a lab bench for two years, so I saw him under quite a bit of pressure.
There are two moments that show his honesty. The first was during a practical exam in our second year. The examiner stepped out of the room for about ten minutes, and a few students started comparing answers. Minh just carried on alone, and when the examiner came back and asked if everything had been fine, he didn't name anyone, but he did say that he thought the results might not reflect everyone's own work. That took nerve, because people weren't happy with him for a while. The second moment was smaller. A shopkeeper near campus once gave him change for a five-hundred-thousand note when he'd paid with a two-hundred. He walked back ten minutes in the rain to return it.
How do I feel about it? Mostly I respect it, but I'll admit it can be uncomfortable too. If you show Minh a plan or a piece of writing, he'll tell you exactly what's wrong with it, and he doesn't really soften the blow. Early on I found that a bit harsh. Over time, though, I realised that his praise actually means something, because you know he isn't just being polite. When he told me my final-year project was genuinely good, I believed him completely. I think that's the real value of an honest friend: you can trust both the criticism and the compliments.